Endothelium-derived relaxing factor (EDRF) is a labile humoral agent which is part of a cascade of interacting agents involved in the relaxation of vascular smooth muscle. EDRF is thus important in the control of vascular resistance to blood flow and in the control of blood pressure. Some vasodilators act by causing EDRF to be released from endothelial cells. (See Furchgott, Ann. Rev. Pharmacol. Toxicol. 24, 175-197, 1984). Recently, Palmer et al have shown that EDRF is identical to the simple molecule, nitric oxide, NO. (Nature 317, 524-526, 1987). It has been hypothesized for years that many nitrovasodilators that mimic the effect of EDRF, like glyceryl trinitrate, amyl nitrite, NaNO.sub.2, and sodium nitroprusside (SNP), do so by virtue of their conversion to a common moiety, namely NO, which is also a vasodilator. (See Kruszyna et al, Tox. & Appl. Pharmacol. 91, 429-438, 1987; Ignarro, FASEB J. 3, 31-36, 1989; Ignarro et al, J. Pharmacol. Exper. Therapeutics 218 (3), 739-749, 1981).
Keefer et al, in U.S. Pat. No. 4,954,526, disclose a method of treating cardiovascular disorders in mammals by administering stabilized nitric oxide primary amine complexes to mammals in need thereof. U.S. Pat. No. 4,954,526 is expressly incorporated by reference.
Spermine is a polyamine (a molecule containing several amino functions) that by itself has been reported to show some hypotensive activity (Marmo, Berrino, Cazzola, Filippelli, Cafaggi, Persico, Spadaro and Nistico, Biomed. Biochim. Acta, 1984, 43, 509-515).
Longhi et al, in Inorganic Chemistry, 1(3), 768-770 (1962), reported that their reaction of N,N'-dimethylethylenediamine with nitric oxide utilizing high pressure techniques produced the compound Me--N(N.sub.2 O.sub.2.sup.-)--CH.sub.2 --CH.sub.2 --N(N.sub.2 O.sub.2.sup.-)Me Me--NH.sub.2.sup.+ --CH.sub.2 --CH.sub.2 --NH.sub.2.sup.+ Me. Based upon preliminary studies made by the present inventors, Longhi et al may have instead produced a compound of the structure CH.sub.3 NH.sub.2.sup.+ CH.sub.2 CH.sub.2 N(N.sub.2 O.sub.2.sup.-)CH.sub.3. No uses are reported by Longhi et al for the compound prepared.